Switch mutex to using anonymous mmap

We don't need an fd backing for this, saves on file descriptors
in use.

Signed-off-by: Jens Axboe <jaxboe@fusionio.com>

diff --git a/mutex.c b/mutex.c
index e33e7cc8f2611a42256e72a3bceddf9e7560b1ef..bbbcccbd0587a7139b247ac4eb38350337fcd912 100644 (file)
--- a/mutex.c
+++ b/mutex.c
@@ -15,44 +15,25 @@
 
 void fio_mutex_remove(struct fio_mutex *mutex)
 {
-       close(mutex->mutex_fd);
        munmap((void *) mutex, sizeof(*mutex));
 }
 
 struct fio_mutex *fio_mutex_init(int value)
 {
-       char mutex_name[] = "/tmp/.fio_mutex.XXXXXX";
        struct fio_mutex *mutex = NULL;
        pthread_mutexattr_t attr;
        pthread_condattr_t cond;
-       int fd, ret, mflag;
-
-       fd = mkstemp(mutex_name);
-       if (fd < 0) {
-               perror("open mutex");
-               return NULL;
-       }
-
-#ifdef FIO_HAVE_FALLOCATE
-       posix_fallocate(fd, 0, sizeof(struct fio_mutex));
-#endif
-
-       if (ftruncate(fd, sizeof(struct fio_mutex)) < 0) {
-               perror("ftruncate mutex");
-               goto err;
-       }
+       int ret, mflag;
 
        mutex = (void *) mmap(NULL, sizeof(struct fio_mutex),
-                               PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+                               PROT_READ | PROT_WRITE,
+                               OS_MAP_ANON | MAP_SHARED, -1, 0);
        if (mutex == MAP_FAILED) {
                perror("mmap mutex");
-               close(fd);
                mutex = NULL;
                goto err;
        }
 
-       unlink(mutex_name);
-       mutex->mutex_fd = fd;
        mutex->value = value;
 
        /*
@@ -97,7 +78,6 @@ err:
        if (mutex)
                fio_mutex_remove(mutex);
 
-       unlink(mutex_name);
        return NULL;
 }
 

diff --git a/mutex.h b/mutex.h
index ac79dc63a6fe536f5acecc9ffd35d34bd95813b5..5938e9592fb0505b5252587d936020717dcf4629 100644 (file)
--- a/mutex.h
+++ b/mutex.h
@@ -8,8 +8,6 @@ struct fio_mutex {
        pthread_cond_t cond;
        int value;
        int waiters;
-
-       int mutex_fd;
 };
 
 extern struct fio_mutex *fio_mutex_init(int);